Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease of unknown etiology, characterized by scaring in the lung and impaired pulmonary function. The pathogenetic mechanisms leading to IPF are poorly understood, and there are currently no effective therapies. Characterization of the molecular and cellular changes occurring in the lung that can be correlated, not only with disease severity, but also with tissue structure and specific cell types is invaluable for the identification of new therapeutic targets. Data from both patients and animal models support a pivotal role for transforming growth factor (TGF)-21 in the development and progression of IPF. Our laboratory has made the sentinel observation that TGF-21 induces heparan sulfate (HS) 6-O-endosulfatase 1 and 2 (Sulf1 and Sulf2), which are novel cell surface sulfatases that remove the 6-O-sulfates from specific HS intra-chain sites. HS is the glycosaminoglycan moiety of the HS proteoglycans (HSPGs), which are major components of the cell surface, basement membrane and the extracelluar matrix. HSPGs interact with and modulate the activity of a myriad of signaling molecules through their HS chains, and it is now well established that HS-protein interactions critically depend on the amount and the positions of the O-sulfate groups, in particular, the 6-O-sulfates. Considering the importance of HS as both a structural and a signaling molecule, and the fact that TGF-21 induces Sulf1 and Sulf2, it is clear that detailed characterizations of these sulfatases in human IPF are important to elucidate their roles in the pathogenesis of this devastating illness. Using human IPF samples from the lung tissue research consortium (LTRC), we propose to test the following hypothesis in this study: Heparan sulfate 6-O-endosulfatases, Sulf1 and Sulf2, are involved in the pathogenesis of idiopathic pulmonary fibrosis. The specific aims are: 1) Examine Sulf1 and Sulf2 expression in control and IPF lungs using real-time quantitative RT-PCR and Western blotting;2) Examine Sulf1 and Sulf2 localization in control and IPF lungs using in situ hybridization and immunohistochemistry;3) Examine the Glyco-gene expression profiles of Sulf1 and Sulf2 expressing cells as well as cells from fibroblastic foci and type II hyperplasia using laser-capture microdissection and Glyco-gene chip array. To our knowledge, this is the first study to address the involvement of Sulf1 and Sulf2 in the pathogenesis of IPF. Our findings could lead to the development of new therapeutic interventions for IPF as well as fibrogenic diseases in other organs. PUBLIC HEALTH RELEVANCE: There are currently over 200,000 patients in the United States and five million people worldwide suffering from idiopathic pulmonary fibrosis (IPF). Examination of Sulf1 and Sulf2 expression in human IPF samples will reveal whether and how Sulf1 and Sulf2 are involved in the pathogenesis of this devastating illness. Findings from this study will help us better understand the molecular mechanisms leading to IPF, and identify new therapeutic targets in treating this disease. (End of Abstract)